Furnaces are known which may be loaded at will fromo ne or any other of their lateral sides. At each one of its side doors the furnace comprises a buffer stop which is positioned in the opening of the door when it is not used so as to block the products which are loaded through the other door and positioned on a roller conveyor.
The present invention relates to a buffer device for a side loading furnace in which the buffer stop may be readily retracted when the loading side is changed.